645

Site number:

645

Authors:

IBC, GGC, MRB

Date recorded:

1991/12/05

Reason Sampled:

Soil weathering and reference for comparison with adjacent disturbed sites

Description:

To the west of the disturbed old Marble Point camp area and about 30m E of a gravelly stream embankment ridge; an area apparently undisturbed by mechanical activity; on a very slight rise on an otherwise level surface

Altitude:

60 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

55 cm

Frozen type:

Hard ice-cemented

Frozen comment:

55cm

Geology

Geological setting:

The surface is a gently undulating till plain formed by retreat of the Wilson Piedmont Glacier; the Marble Point region is an old landscape, with deposits of phillipsite, buried soils and oxidised gneiss, which have been covered by advances of the grounded Ross Ice Shelf; later ice retreat and glaciological features have been controlled by changes in the stranded Wilson Piedmont Glacier; the till mantle is patchy and dominated largely by locally occurring rocks; granodiorite, granite, marble, gneiss, and dolerite

Patterned ground:

Nil

Surface weathering or surface features:

Some clasts with distinct oxide staining; a well developed pavement of mainly subangular clasts; carbonate coatings are common

Soil

Soil parent material:

Gravelly till from mixed granodiorite, gneiss and marble

Previous disturbance:

No apparent mechanical disturbance but extensive surface disturbance from walking during earlier camp activity is likely

Soil weathering stage:

1 (Campbell & Claridge 1975)

Soil moisture status:

Recent snow cover completely thawed; soil is slightly moist

Biological activity:

Nil at site but moss and cyanobacteria locally common